Figure 4. Phylogenetic relationships and dating.

Mitochondrial phylogeny and approximate divergence times for the common cuckoo Cuculus canorus and closely related species. The analysis is based on a comprehensive cuculiform data set representing 119 of 141 recognized cuckoo species²¹ augmented with additional data for representative samples from this study (see Supplementary Fig. 2 for the complete phylogeny). Blue colour indicates common cuckoo lineages laying immaculate blue eggs. All nodes have posterior probabilities of 1, except as indicated. Approximate divergence times are shown with 95% highest posterior density intervals. See Supplementary Information for details on samples and calibration.